Track-type vehicles, such as hydraulic excavators, normally have a substantial gauge width between the track roller frames in order to increase the overall stability of the vehicle during earthworking operations. Because this gauge width frequently exceeds the legal shipping width as dictated by various governmental regulations, the track roller frames of the vehicle must be disassembled from the car body frame for transportation purposes. Such procedures are time consuming and expensive to carry out.
In the past, the superstructure and car body frame of a considerable number of these vehicles have been mounted on the opposite undercarriages by utilizing a relatively large number of vertically oriented fastening devices disposed at each of the four legs of the car body frame. Normally too, a pair of horizontally disposed mounting surfaces on each of the undercarriages supports a pair of these laterally extending legs, and with this arrangement the legs of the larger machines extend so far as to present an overall width beyond the permissible shipping limits of approximately 8 - 12 feet or 2.5 - 3.5 meters.
When the abutting mounting surfaces are reoriented from the usual horizontal disposition to a vertical disposition in order to decrease the overall width of the car body frame, other problems are experienced. For example, it has been found that an excessive number of fastening bolts must be used to provide a sufficiently strong joint and to particularly resist the heavy shear loads that occur in use. In order to reduce the number of bolts, close fitting cylindrical pins or dowels have been projectingly mounted on one of the members for guided insertion into a corresponding number of openings on the other. For example, reference is made to the car body leg construction disclosed in U.S. Pat. No. 3,037,571 issued to L. L. Zelle on June 5, 1962. Here also, such supplementary shear-resisting elements give rise to costly manufacturing problems. Specifically, the relatively large diameter cylindrical pins and mating holes must be precisely aligned in order to adequately transfer the heavy loads between the members. This is not only costly, but adds to the complexity of the assembling operation.